A healthy human eye has an anterior chamber and a posterior chamber separated from one another by an iris. Within the posterior chamber is a capsular bag which holds the eye's natural crystalline lens.
Light enters the eye by passing through a cornea. The cornea and crystalline lens act together to direct and focus the light onto a retina. In response to the sharpness of the image received by the retina, the brain operates to contract or relax ciliary muscles.
In an eye where the natural crystalline lens has been damaged (e.g., clouded by cataracts), the natural lens is no longer able to properly focus and/or direct incoming light to the retina. As a result images become blurred. A well known surgical technique to remedy this situation involves removal of a damaged crystalline lens through a hole in the capsular bag known as a capsularhexis (also referred to simply as a rhexis). Subsequently, an artificial lens known as an intraocular lens (IOL) can be placed into the evacuated capsular bag through the rhexis.
Conventional IOLs are typically fixed-focus lenses. Such lenses are usually selected to have a power such that the patient has a fixed focus for distance vision, and the patient requires spectacles to permit near vision. In recent years extensive research has been carried out to develop IOLs having variable focus capability. Such IOLs are known as accommodating IOLs (AIOLS). AIOLs may be single-element or multi-element lenses.
AIOLs permit a wearer to have accommodative vision. AIOLs are typically located in the posterior chamber (e.g., in the capsular bag) and provide variable focal power in accordance with tension or a lack of tension exerted on the capsular bag as a result of contraction and relaxation of the ciliary muscle.
One example of a single-element AIOL is given in U.S. application Ser. No. 11/974,364, filed Oct. 11, 2007. The substance of said application is hereby incorporated by reference. A lens similar in relevant portions to the lens in FIG. 1A of said application is reproduced herein as FIG. 1. FIG. 1 illustrates an AIOL 100 comprising an optic 102 (also commonly referred to as an optical element), and two haptics 108a and 108b. The haptics comprise haptic plates 104a and 104b, respectively; and each haptic plate has two haptic filaments 106a and 106b, and 106c and 106d (also commonly referred to as loops).
Insertion of lenses which include a relatively complex haptic structure, such as lens 100, into an eye has proven complicated, particularly when insertion is performed using an IOL injector. For example, insertion using an injector (also referred to as injection) may result in haptic damage and/or incorrect orientation of the haptics.